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Carmen Torres

Publications and source records attributed to Carmen Torres.

36 records · Page 2Linked to original sources

High tolerance of wild Lactobacillus plantarum and Oenococcus oeni strains to lyophilisation and stress environmental conditions of acid pH and ethanol.

A total of 76 Lactobacillus plantarum and Oenococcus oeni wild strains were recovered from traditionally elaborated Spanish red wines and were investigated with respect to their response to acid pH, lyophilisation, temperature and ethanol concentrations which are normally lethal to lactic acid bacteria. Both L. plantarum and O. oeni strains were able to grow at pH 3.2, were highly resistant to lyophilisation treatment and proliferated in the presence of up to 13% ethanol at 18 degrees C. Therefore, it is shown that both species are highly tolerant to stress conditions and that similarly to O. oeni strains, L. plantarum strains are of interest in beverage biotechnology.

Culture Media↗

Outbreak of SHV-5 beta-lactamase-producing Klebsiella pneumoniae in a neonatal-pediatric intensive care unit in Spain.

The objective was to analyze the beta-lactamase genes and the clonal relationship in a series of 12 clinical Klebsiella pneumoniae strains resistant to ceftazidime or cefotaxime (MIC >/=16 microg/ml) recovered in the neonatalpediatric intensive care unit (ICU) ward of a Spanish hospital during a 1-year period. TEM, SHV, CTX-M, CMY, or FOX beta-lactamase genes were analyzed by PCR and sequencing. The clonal study was performed by pulsed-field gel electrophoresis (PFGE) using XbaI. All but one of the 12 K. pneumoniae strains harbored the bla (SHV-5) gene, and the bla TEM-1a gene was also detected in one of them. These 11 strains belonged to two different clonal types: A (9 strains) and B (2 strains) and were grouped in the subtypes A(1) (6 strains), A(2), A(3), A(4), B(1), and B(2) (1 strain each). The clonal type A strains were isolated from 9 patients (in five cases from blood) during a 6-month period. The remaining K. pneumoniae strain harbored both the bla (SHV-11) + bla (CTX-M-14) genes and showed the clonal type C. A nosocomial outbreak by a SHV-5-producing multiresistant K. pneumoniae is reported in Spain in a neonatal-pediatric ICU ward. This is the first description of a K. pneumoniae harboring both the bla (SHV-11) and bla (CTX-M-14) genes in Spain.

Cross Infection↗

Pediatric infection due to multiresistant Salmonella enterica serotype Infantis in Honduras.

We report the case of a pediatric patient with a Salmonella enterica serotype Infantis infection. Detailed microbiological investigation revealed that this isolate carries four beta-lactamase genes (bla(TEM-1b) variant, bla(SHV-5), bla(CTX-M-15), and bla(CMY-2)) conferring resistance to all beta-lactams but imipenem. This is the first report of a Salmonella isolate with CTX-M and AmpC enzymes on the American continent, the first report of bla(CMY-2) in Salmonella serotype Infantis, and the first report of bla(CTX-M-15) in the genus Salmonella.

Drug Resistance, Multiple, Bacterial↗

Mutations in gyrA and parC genes in nalidixic acid-resistant Escherichia coli strains from food products, humans and animals.

Mutations in quinolone targets were analysed in 80 unrelated nalidixic acid-resistant (NALR) Escherichia coli strains whose nalidixic acid and ciprofloxacin MICs ranged from 32 to >256 mg/L and 0.03-64 mg/L, respectively. These strains were isolated from food products (23) and faecal samples from humans (15) and healthy animals (42). Thirteen nalidixic acid-susceptible (NALS) E. coli strains were also analysed. Mutations in gyrA and parC genes were studied by PCR and sequencing. No amino acid changes were detected in GyrA or ParC proteins of the 13 NALS strains. A single change in the GyrA protein was detected in all 61 NALR strains with ciprofloxacin MICs </= 2 mg/L with the following substitutions (number of strains): Ser-83-->Leu (54), Ser-83-->Ala (one), Ser-83-->Val (one), Asp-87-->Asn (two), Asp-87-->Tyr (two) and Asp-87-->Gly (one). A double change in GyrA was found in 18 of 19 NALR strains with ciprofloxacin MICs >/= 4 mg/L. Amino acid substitutions were Ser-83-->Leu, with an additional change [Asp-87-->Asn (15), Asp-87-->Tyr (two) or Asp-87-->His (one)]. The remaining strain (ciprofloxacin MIC 4 mg/L) showed a single Ser-83-->Leu substitution. In respect of the ParC protein, a single change at Ser-80 or Glu-84 was found in 25 of 42 strains, with ciprofloxacin MICs ranging from 0.5 to 32 mg/L. A double substitution (Ser-80-->Ile and Glu-84-->Gly) was found in one strain (ciprofloxacin MIC 64 mg/L). No amino acid changes were detected in the GyrB protein of 18 NALR strains.

Animals↗

Synoviocyte-derived CXCL12 is displayed on endothelium and induces angiogenesis in rheumatoid arthritis.

CXCL12 (stromal cell-derived factor-1) is a potent CXC chemokine that is constitutively expressed by stromal resident cells. Although it is considered a homeostatic rather than an inflammatory chemokine, CXCL12 has been immunodetected in different inflammatory diseases, but also in normal tissues, ant its potential functions and regulation in inflammation are not well known. In this study, we examined the cellular sources of CXCL12 gene expression and the mechanism and effects of its interactions with endothelial cells in rheumatoid arthritis synovium. We show that CXCL12 mRNA was not overexpressed nor induced in cultured rheumatoid synoviocytes, but it specifically accumulated in the rheumatoid hyperplastic lining layer and endothelium. CXCL12 gene expression was restricted to fibroblast-like synoviocytes, whereas endothelial cells did not express CXCL12 mRNA, but displayed the protein on heparitinase-sensitive factors. CXCL12 colocalized with the angiogenesis marker alpha(v)beta(3) integrin in rheumatoid endothelium and induced angiogenesis in s.c. Matrigel plugs in mice. The angiogenic activity of rheumatoid synovial fluid in vivo was abrogated by specific immunodepletion of CXCL12. Our results indicate that synoviocyte-derived CXCL12 accumulates and it is immobilized on heparan sulfate molecules of endothelial cells, where it can promote angiogenesis and inflammatory cell infiltration, supporting a multifaceted function for this chemokine in the pathogenesis of rheumatoid arthritis.

Animals↗

Intestinal colonization by vanA- or vanB2-containing enterococcal isolates of healthy animals in Spain.

Fecal samples of healthy animals (66 pigs, 22 pets) recovered during 1998 in La Rioja, Spain, were analyzed for vancomycin-resistant enterococci colonization. Vancomycin resistance mechanisms were analyzed by PCR and sequencing. vanA-containing enterococci were detected in 3 of 66 samples (4.5%) and 5 of 22 samples (22.7%) of the pig and pet samples, respectively. Seven unrelated pulsed-field gel electrophoresis (PFGE) patterns were detected among the 8 vanA isolates (7 Enterococcus faecium, 1 E. faecalis). The tet(M) gene was present in all eight vanA enterococcal isolates, while the erm(B) and aac(6')-Ie-aph(2")-Ia genes were detected in 6 and 3 isolates, respectively. Colonization by vanC-1-containing enterococci (E. gallinarum) was demonstrated in 3% and 4.5% of the pig and pet samples. The aac(6')-Ie-aph(2")-Ia, ant(6)-Ia, aph(3')-IIIa, erm(B) and tet(M) genes were identified in one of the E. gallinarum isolates from a pig fecal sample. One vanB2-containing E. hirae strain was detected in the fecal sample of a healthy pig. In this isolate, the vanB2 gene cluster was integrated into the Tn5382-like element, as demonstrated by specific PCRs and sequencing. The tet(M) and erm(B) genes were also detected in this isolate. This is the first report in which a vanB2-containing enterococci is detected in animals and in E. hirae.

Animals↗

Beta-lactamase characterization in Escherichia coli isolates with diminished susceptibility or resistance to extended-spectrum cephalosporins recovered from sick animals in Spain.

A total of 1439 Escherichia coli isolates from sick animals were received from the Spanish Network of Veterinary Antimicrobial Resistance Surveillance (VAV) from 1997 to 2001. Antimicrobial susceptibility tests were performed and diminished susceptibility to cefotaxime and ceftazidime was identified in 2.5% and 2.8% of the isolates, respectively. Beta-lactamase characterization was carried out in the group of 20 E. coli isolates with both characteristics. The MIC ranges of different beta-lactams showed by these 20 isolates were as follows (in microg/ml): ampicillin (64-->256), amoxicillin-clavulanic acid (4-64), ticarcillin (8-->128), cefazolin (32-->256), cefoxitin (4-->128), cefotaxime (1-64), ceftazidime (2-->64), ceftriaxone (0.5-64), imipenem (< or = 0.06-0.25), and aztreonam (2-->32). TEM, SHV, CMY, and FOX beta-lactamase genes were analyzed by PCR and sequencing. The beta-lactamase genes detected were the following ones (number of isolates): bla(TEM-1b) (3), bla(TEM-1a) (1), bla(TEM-30f) (2), bla(TEM-1b) + bla(CMY-2) (2), and bla(SHV-12) (1). Sequences of the promoter and/or attenuator region of the chromosomal ampC gene were studied in all the 20 isolates. Mutations at position -42 or -32 were detected in 16 isolates and these mutations were associated with the presence of a TEM type beta-lactamase in 6 isolates. Besides, a high variety of plasmidic beta-lactamases was detected including TEM-30 and CMY-2. To our knowledge, this is the first time that TEM-30 beta-lactamase has been detected in E. coli isolates of animal origin.

Animal Diseases↗

Mechanisms of antibiotic resistance in Escherichia coli isolates obtained from healthy children in Spain.

Antibiotic resistance and mechanisms involved were studied in Escherichia coli isolates from fecal samples of healthy children. Fifty fecal samples were analyzed, and one colony per sample was recovered and identified by biochemical and molecular tests. Forty-one E. coli isolates were obtained (82%). MIC testing was performed by agar dilution with 18 antibiotics, and the mechanisms of resistance were analyzed. Ampicillin resistance was detected in 24 isolates (58.5%), and blaTEM, blaSHV, and blaOXA type genes were studied by PCR and sequencing. The following beta-lactamases were detected (number of isolates): TEM (20), SHV-1 (1), and OXA-30 (1). The number of aminoglycoside-resistant isolates detected was as follows: streptomycin (15), tobramycin (1), gentamicin (1), and kanamycin (4). The aac(3)-IV gene was detected in the only gentamicin-resistant isolate. Nine (22%) and 2 (5%) isolates showed nalidixic acid (NALR) and ciprofloxacin resistance (CIPR), respectively. Mutations in GyrA and ParC proteins were shown in both NAL(R)-CIP(R) isolates and were the following: (1) GyrA (S83L + D87N), ParC (S801); and (2) GyrA (S83L + A84P), ParC (S80I + A108V). A single mutation in the S83 codon of the gyrA gene was found in the remaining seven NAL(R)-CIP(S) isolates. Tetracycline resistance was identified in 21 isolates (51%) and the following resistance genes were found (number of isolates): tetA (12), tetB (5), and tetD (1). Chloramphenicol resistance was detected in five isolates (12%). These results show that the intestinal tract of healthy children constitutes a reservoir of resistant bacteria and resistance genes.

4-Quinolones↗

Beta-lactamases in ampicillin-resistant Escherichia coli isolates from foods, humans, and healthy animals.

TEM-, SHV-, and OXA-type beta-lactamases were studied by PCR with 124 ampicillin-resistant (AMP(r)) Escherichia coli isolates recovered from foods of animal origin (n = 20) and feces of humans (n = 49) and healthy animals (n = 55). PCR showed that 103 isolates were positive for TEM and negative for SHV and OXA. Three E. coli isolates showed a positive reaction for OXA, and one showed a positive reaction for SHV. The remaining 17 E. coli isolates were negative for the three enzymes by PCR. Fifty-seven of the 103 bla(TEM) amplicons were sequenced. Different molecular variants of bla(TEM-1) were found in 52 isolates: bla(TEM-1a) (n = 9), bla(TEM-1b) (n = 36), bla(TEM-1c) (n = 6), and bla(TEM-1f) (n = 1). Four inhibitor-resistant TEM (IRT) beta-lactamase-encoding genes were also detected: bla(TEM-30c) (IRT-2), bla(TEM-34b) (IRT-6), bla(TEM-40b) (IRT-11), and bla(TEM-51a) (IRT-15). A new bla(TEM) gene, named bla(TEM-95b), which showed a mutation in amino acid 145 (P-->A) was detected. It was found in a food isolate of chicken origin (AMP(r), amoxicillin-clavulanic acid susceptible). The promoter region in 24 bla(TEM) amplicons was analyzed, and the weak P3 promoter was found in 23 of them (bla(TEM-1) in 20 amplicons and bla(TEM-51a), bla(TEM-30c), and bla(TEM-95b) in 1 amplicon each). The strong Pa/Pb promoter was found only in the bla(TEM-34b) gene. No extended-spectrum beta-lactamases were detected. Mutations at position -42 or -32 in the ampC gene promoter were demonstrated in 4 of 10 E. coli isolates for which the cefoxitin MIC was >/=16 micro g/ml. Different variants of bla(TEM-1) and IRT bla(TEM) genes were found among the AMP(r) E. coli isolates from foods and the feces of humans and healthy animals, and a new gene, bla(TEM-95b) (P3), was detected.

Ampicillin↗

Mutations in ribosomal protein L16 and in 23S rRNA in Enterococcus strains for which evernimicin MICs differ.

Mutations in ribosomal protein L16 and in 23S rRNA were investigated in 22 Enterococcus strains of different species and for which the MICs of evernimicin differ (MICs, 0.023 to 16 micro g/ml). Amino acid changes (Arg56His, Ile52Thr, or Arg51His) in protein L16 were found in seven strains, and a nucleotide G2535A mutation in 23S rRNA was found in 1 strain among 13 for which the MICs are > or =1 micro g/ml.

Amino Acid Substitution↗

Antibiotic resistance in Staphylococcus isolates obtained from fecal samples of healthy children.

Thirty-nine Staphylococcus isolates with different mechanisms of resistance were recovered from the feces of 50 healthy children and tested for their susceptibilities to 17 antibiotics. The percentages of resistance of the staphylococci to some antibiotics were as follows: penicillin, 87%; erythromycin, 64%; tobramycin, 36%; tetracycline, 20.5%; kanamycin, 15%; and gentamicin, 13%. The mecA gene was detected in nine coagulase-negative staphylococci.

Aminoglycosides↗

[Interpretative reading of the antibiogram in gram-positive cocci].

Resistance to methicillin in Staphylococcus is related to expression of the gene mecA, and implies resistance to all beta-lactams. Breakpoints for interpretation of this mechanism differ in S. aureus and in coagulase-negative species. In relation to macrolides-lincosamides-streptograminsB, the most frequent mechanism among resistant strains is expression of methylases (erm genes). Topoisomerase changes caused by point mutations and expression of the efflux pump NorA determine resistance to quinolones, but there are great differences on the activity of different compounds, which makes interpretative reading difficult. Strains of S. aureus with intermediate susceptibility to glycopeptides (GISA strains) have been recently described. In Spain, there is a high percentage of S. pneumoniae strains intermediate or resistant to penicillin, and a low percentage of strains intermediate or resistant to third generation cephalosporins, because of mutations in genes encoding penicillin-binding proteins. The most frequent phenotype of resistance to macrolides in this species is caused by methylase production. Resistance to quinolones is still uncommon, and is related to the mechanisms previously indicated for Staphylococcus, but clinical interpretation of the antibiograma for this organism is even more complex. No strains of S. pyogenes resistant to penicillin have yet been described. In Spain the most common phenotype of resistance to macrolides in S. pyogenes is determined by efflux pumps (mef genes), affecting 14- and 15-membered macrolides. E. faecalis is usually susceptible to ampicillin, in contrast to E. faecium. Enterococci show intrinsic resistance to aminoglycosides, but still remain susceptible to the combination of these antimicrobials and cell-wall active agents. Strains expressing different aminoglycoside-modifying enzymes became resistant to the combination. Glycopeptide-resistant strains of enterococci are uncommon in our country, but several genotypes, of which vanA is the most relevant from a clinical point of view, have been described in other regions.

Drug Resistance, Bacterial↗

Patients' and nurses' perceptions of quality nursing activities.

Nurses and patients come from varying backgrounds and have different life experiences. Their perceptions regarding what comprises quality nursing care may differ. The objective of this article was to determine whether there is a difference in the perceived importance of nursing activities from the point of view of patients and nurses. If differing perceptions were found, the goal would then be to increase nursing awareness of these differences. A convenience sample of 30 nurses and 30 patients on a medical-surgical unit were surveyed about nursing care using a 41-item questionnaire. Data obtained were divided into four classes of nursing activities: psychosocial, physical, safety, and indirect. There was a significant difference in the perceived importance of nursing activities by nurses and patients in the psychosocial and safety categories. Nursing activities that may not be recognized as such by patients, or which are not seen as important to quality care, should be clarified for patients. Clarification may also be useful in helping patients to understand the professional nursing role. In addition, this insight may heighten patient satisfaction with caregiving.

Adult↗